irishjohnnie | 3 years ago | on: AMD Announces 7950X3D, 7900X3D Upto 128MB L3 Cache
I believe it is both a scheduling and memory allocation/loading issue. It is interesting that caches are NUMA but main memory is not.
irishjohnnie's comments
irishjohnnie | 3 years ago | on: DARPA wants to combine traditional sealift and airlift
Are you referring to the ballpark "specifications" in the article? If so, I don't know of any material that can withstand the stresses of the weights and speeds mentioned in it ... unless you are going for really low wing loading (think dirigible).
irishjohnnie | 4 years ago | on: The Great Resignation? More Like the Great Renegotiation
Current inflation is mostly supply-side driven. Having said that, M2's biggest jump in its history was in early 2020 (see https://fred.stlouisfed.org/series/M2SL). Its slope before and after is more or less the same. However, I don't think inflation will lag it by more than a year.
irishjohnnie | 4 years ago | on: How to design a sailing ship for the 21st century?
Yup. OceanWings by VPLP https://www.hellenicshippingnews.com/vplp-design-signs-its-f...
irishjohnnie | 5 years ago | on: A new design ship in the Philippines is partly powered by wave energy
> It’s honestly a shame that we didn’t keep pursuing sail technology ...
You mean something like this? https://www.top-yachtdesign.com/oceanwings-by-vplp/
irishjohnnie | 5 years ago | on: Americans are getting more nervous about what they say in public
ICYMI lots of issues with that study, https://academic.oup.com/aje/article/doi/10.1093/aje/kwaa155... https://academic.oup.com/aje/article/doi/10.1093/aje/kwaa156...
irishjohnnie | 5 years ago | on: Americans are getting more nervous about what they say in public
It also looks like that study is still in the peer review process. It has the "Accepted Manuscript" flag (https://academic.oup.com/aje/pages/Instructions_To_Authors) and has at least one major error, https://academic.oup.com/aje/article/doi/10.1093/aje/kwaa155...
irishjohnnie | 5 years ago | on: Americans are getting more nervous about what they say in public
> Covid is an autoimmune disease. The Over active immune response is what is killing people.
The virus triggers an acute immune response. This is not the same as an autoimmune disease, it may be the opposite. Also, people with certain blood types that have better clotting ability seem to be at a disadvantage.
irishjohnnie | 5 years ago | on: Americans are getting more nervous about what they say in public
There is also a glaring conflict of interest regarding the author of that paper and some manufacturers of the drugs in question, https://academic.oup.com/aje/article/doi/10.1093/aje/kwaa156...
irishjohnnie | 6 years ago | on: Why should I have written ZeroMQ in C, not C++ (2012)
I missed this in my previous reply ...
> Look at all the results. Even before that exceptions are more often a win than a loss.
The blog post you linked to effectively says "it depends"
irishjohnnie | 6 years ago | on: Why should I have written ZeroMQ in C, not C++ (2012)
> But on 64-bit windows the default exception handling (SEH) uses a similar mechanism than Linux and should have comparable performance.
AFAIK SEH in Windows calls RaiseException() which in turn causes a user/kernel mode transition, probes for exception/termination handlers, and vectored exception handlers depending on the severity. It's been a while but I'm not sure the code GCC generates in Linux is quite like this.
irishjohnnie | 6 years ago | on: Why should I have written ZeroMQ in C, not C++ (2012)
> benchmarks have shown that exceptions are generally faster
The blog post you linked to says "Immediately we see that once the stack depth grows above a certain size (here 200/3 = 66), exceptions are always faster. This is not very interesting, because call stacks are usually not this deep (enterprise Java notwithstanding). For lower depths there is a lot of noise, especially for GCC ..." So ... not exactly "generally faster".
Also, the test is only for Linux. The same test on Windows/VC++ will probably run a lot slower ... again not "generally faster"
irishjohnnie | 6 years ago | on: Bosch Smart glasses: A tiny laser array paints images directly onto your retina
irishjohnnie | 8 years ago | on: America’s Fastest Spy Plane May Be Back and Hypersonic
Video from SciTech conference https://livestream.com/accounts/6056055/events/8001237/video... starting at around 41 minutes
irishjohnnie | 8 years ago | on: AMD's Future in Servers: New 7000-Series CPUs Launched and EPYC Analysis
I was referring to the RTL-based IP that goes into each subsystem of the CPU, hence the analogy to code. You're talking about compiler instruction scheduling, a lot of which are a bunch of non-AI algorithms. If I'm missing something, I would appreciate the references to the functionality you're referring to.
irishjohnnie | 8 years ago | on: AMD's Future in Servers: New 7000-Series CPUs Launched and EPYC Analysis
Probably not. Do you use AI to write code?
irishjohnnie | 8 years ago | on: AMD's Future in Servers: New 7000-Series CPUs Launched and EPYC Analysis
Wow! AMD EPYC + Xilinx FPGA!
irishjohnnie | 8 years ago | on: Hardware is the new software
You mean like Xilinx's Zynq? https://www.xilinx.com/products/silicon-devices/soc/zynq-700...
irishjohnnie | 9 years ago | on: Disruptor: High performance alternative to bounded queues (2011) [pdf]
Ring buffers are also used in web servers, database servers, different kinds of device drivers protocol stacks, constrained embedded devices, etc.
irishjohnnie | 9 years ago | on: Disruptor: High performance alternative to bounded queues (2011) [pdf]
IIRC, the data structure that they used was not thread-safe. There eventually had to be an interlocked compare exchange operation which slowed throughput. Also, I couldn't imagine this working correctly in out-of-order cores without memory barriers at the very least.
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